Supporting means and recoil spring for a gun mount



March 31, 1959 H. c. FOSTER SUPPORTING MEANS AND RECOIL SPRING FOR A GUN MOUNT Filed Dec. 28. 1953 INVENTOR. HARRY CLARK FOSTER,

A TToRA/EYS.

United States Patent SUPPORTING MEANS AND RECOIL SPRING FOR A GUN MOUNT Harry Clark Foster, Rosewood Heights, 111., assignor to Olin Mathieson Chemical Corporation, a corporation of Virginia Application December 28, 1953, Serial No. 400,431

2 Claims. (Cl. 89-44) This invention relates generally to guns, and more particularly, to gun mounts of the type providing recoil absorption and training adjustment.

In the cement and refractory industries, aneight-gauge gun is used to destroy the clinker masses that build up and adhere to the inner surface of rotary kilns. The gun is set up on a mount at one end of the kiln, and solid slugs are fired into the clinker ring at a rapid rate, the ring thereby being broken up before it has cooled. This type of'service requires an inexpensive, troublefree, rugged mount to absorb recoil and contain mechanism for aiming the gun. Moreover, the mount must be lightweight for convenient handling, and the barrel should be easy to replace, inasmuch as barrel life is short.

Heretofore, difiiculties have been encountered in providing a satisfactory training mechanism. In particular, it has been necessary to include a clamping device to lock the training adjustment, and where training mechanism has been included, the parts tend to become fouled. It is accordingly an object of the present inventionto provide an inexpensive, trouble-free gear training control, which will hold adjustment without locking means.

Recoil absorption has also presented a problem. Ideally, the barrel carriage should be a casting, but in such event, it is necessary to include a rebound spring as well as a recoil spring. Where rebound springs have been used, however, they have interfered with barrel assembly. It is accordingly an object of the present invention to provide an improved rebound spring system, and in particular, to simplify the task of barrel replacement.

Briefly, my improved gun mount comprises a barrel carriage pivotally carried for swinging movement about a vertical axis upon a platform, which platform is adjustably supported for swinging movement about a horizontal axis. In assembly, the carriage and platform provide a cavity which contains the training gears. A worm screw is journaled transversely on the platform in en- 'gagement with a worm wheel, also carried by the platform on a vertical axis. An overlying pinion keyed to the worm wheel then engages a gear segment, which is fixed to the carriage. With this arrangement, the operating surfaces are enclosed and sufiicient friction is achieved to permit elimination of the locking means heretofore thought necessary.

The gun barrel is slidably held by the carriage, and a spring-pressed element is mounted on the carriage for movement with respect to both the carriage and barrel. More specifically, the barrel is slidably received through a hearing, which itself is slidably held by the carriage.

A recoil spring is telescoped over the forward portion of the barrel, and a relatively stifier rebound spring is telescoped over the bearing. This bearing is biased rearwardly, and a head at one end thereof engages the receiver, whereas a nut on the other end provides for convenient assembly and setting of the spring force. This nut, in turn, is formed with an inner threaded segment freed from the main body of the nut for inward move merit and adapted to be clamped against the threads on the bearing by a set screw, thereby to lock the nut without damage to the threads.

Other features of the invention will be in part apparent from and in part pointed out in the following detail description taken in connection with the accompanying drawings, in which:

Fig. 1 'is a side elevation of the gun mount of this invention; Fig. 2 is an enlarged vertical section taken longitudinally to show details of the training and rebound mechanism;

Fig. 3 is a horizontal section taken on the line 3-3 of Fig. 2; and

Fig. 4 is a transverse, vertical section taken on the line 4-4 of Fig. 2.

' a bracket 1 is permanently fastened to the kiln below the gun port, so that the gun can be quickly emplaced. The mount is portable and comprises a platform 3, a front leg 5 and a rear leg 7, all hingedly connected at their ends. The rear leg 7 may be adjustable in length,

' thereby to control gun elevation, and the ends of pivot pin 9 serve as trunnions for hanging the mount on the bracket 1. Firing of numerous rounds of slugs as rapidly as possible is desired before the kiln has had a chance to cool excessively because the ring is more easily broken.

' at the higher temperatures.

In addition, the mount includes a carriage 11, in which the barrel 13 may recoil and by means of which the barrel is trained horizontally. This carriage 11 preferably is a casting having a bottom surfaced for sliding cooperation with the platform 3, there being, a pivot member 14 adjacent the forward part of the platform and training mechanism adjacent the rear end. A retaining rail 12 secured to the carriage over the rear margin of the platform 3 maintains the parts against separation. The gun barrel 13 extends through an apertured front shoulder or barrel supporting means 15 formed on the carriage, and a recoil spring 17 is telescoped over the forwardly projecting portion of the barrel. This spring may have a large number of spaced turns, and it is conveniently secured under compression by locking nuts 19 screwed onto a threaded part of the barrel.

The barrel extends rearward through a second apertured shoulder 21 of the carriage forming another part of the supporting means and extends for fixation into a block 23 constituting the receiver. The breech mechanism is not significant to this invention, hence is not described, apart from noting that a bronze guide member 25 is secured to the block 23 within a slot 27 at the end of the carriage 11. The part 25 and slot 27 serve to prevent the barrel from rotating in the mount.

Referring more particularly to Fig. 2 of the drawings, the rear barrel-supporting shoulder 21 slidably receives a sleeve member or bearing 29 having a rearwardly spaced head 31 forming an outwardly extending flange, which is in abutting engagement with a forward-facing shoulder 39 formed on either the rear end of the barrel or on the receiver 23. A rebound spring 35 is compressed between the head 31 and shoulder 21, and a flange-like retainer such as nut 37 is threaded over the opposite end of the bearing on the other side of the shoulder. The rebound spring has few widely spread turns compared to the recoil spring and has a high spring rate in comparison to the recoil spring, the greater stiffness being achieved by forming the spring from a heavier grade of metal strip. In other words, there is a sub- Patented Mar. 31, 1959 stantial difference between the inside and outside diameters of spring 35. Necessarily, the manufacture of such a heavy spring does not admit of fine control, but by selecting a spacer washer 33 f suitable thickness, the parts are readily assembled with the spring properly compressed when the nut 37 is screwed up to a limiting shoulder on the bearing 29 where it is locked in abut? ment with the supporting means.

In operation, the barrel recoils through the bearing 29 and, in return under the bias of the recoil spring 17, is cushioned by forward movement of the bearing against the bias of the rebound spring 35. It will be noted the springs are entirely independent of one another in character, assembly and adjustment. Moreover, the barrel assembly operation is not made difiicult by the springs. Indeed, the barrel can be replaced without removing the rebound spring, merely by removing the nuts 19 and recoil spring 17, the barrel and receiver being withdrawn rearwardly.

Referring to Fig. 4, comment is made on the method employed in locking the nut 37, which can be of the spanner wrench type. A slot is cut radially at 41 and then concentrically over an are 43, thereby freeing a section 45 of the threads for inward movement with re spect to the main body of the nut. A pair of set screws 47 are located over this section 45, and when these screws are tightened, the nut 37 becomes locked in position but without damage to the threads. Such a nut should be made of steel so that there would be an inherent resiliency, which will cause the segmented section 45 to release its grip when the set screws 47 are loosened.

Reference is now made to Figs. 2 and 3 for a descriptionof the training mechanism. The platform 3 is formed with an upwardly opening cavity 49, and a worm 51 is journaled transversely for engagement with a contained worm wheel 53. The worm 51 is externally manipulated by means of handle 55. The carriage piece 11 also has a cavity 57, and a toothed insert 59 is fixed therein for engagement with. a contained pinion 61. The pinion 61 and worm wheel 53 are keyed to a vertical shaft 62, which is journaled in the platform at 63 and in a removable partition plate 65, also supported by the platform. It will be noted that the teeth of insert 59 are on a large diameter circle so that considerable mechanical advantage is developed, which when added to that of the worm drive 5153, affords fine control over training adjustments and obviates any need for a brake or clamp to hold the adjustment. Moreover, the parts are readily assembled, and in assembly are protected from injury.

From the foregoing description, it will be apparent to those skilled in the art that the gun mount herein disclosed is inexpensively manufactured, readily disassembled and assembled, light in weight, and trouble-free in operation. Although one embodiment of the invention is disclosed in detail, it should be understood that the features thereof may be modified and adapted for various applications, without departing from the spirit of the invention, or the scope thereof, as set forth in the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In apparatus of the character described having a gun carriage and a gun barrel mounted thereon, the improvement comprising fixed supporting means on said carriage through which said barrel extends, a sleeve member slidably received in said supporting means and said barrel being slidably received in said sleeve member, said sleeve member projecting rearwardly with respect to said means and also forwardly through said means, and said sleeve member. also being formedwith an outer radially extending flange at one end and having a flangelike retainer adjustably mounted on one of said projecting portions of said sleeve member at the end opposite said flange in locked relationship, a short rebound spring having stiff spaced turns widely different in inside and outside diameter extending over said sleeve member between said supporting means and one of said flange and retainer while the other of said flange and retainer is normally in abutment with said supporting means for adjustably drawing one of said flange and retainer with respect to said supporting means to compress said rebound spring to a predetermined compression against said supporting means, said barrel having shoulder means adjacent its rear end engageable with the sleeve member, a recoil spring relatively long and soft with respect to said rebound spring and telescoped over the barrel for wardly of said supporting, means and a lock-nut threaded over the forward end of said barrel in engagement with said barrel and in abutment with the front end of said recoil spring for compressing said recoil spring to draw said barrel shoulder against said sleeve member, thereby minimizing oscillation of said barrel and barrel receiving sleeve while permitting easy removal of, said barrel for inspection, repair or replacement.

2. The improvement of claim 1 wherein the supporting means comprises a front support and a rear support and wherein the flange-like retainer is mounted threadedly between said supports and the recoil spring is compressed against the front support.

References Cited in the file of this patent UNITED STATES PATENTS 1,183,190 Hansell May 16, 1916 1,757,244 Green May 6, 1930 2,075,087 Birkigt Mar. 30, 1937 2,249,310 Braun et al July 15, 1941 2,280,270 Stoner Apr. 21, 1942 2,293,069 McNeill et al Aug. 18, 1942 2,303,327 Coupland Dec. 1, 1942 2,312,508 Ulrich et al. Mar. 2, 1943 2,380,470 Schneider July 31, 1945 2,395,211 Bell et al. Feb. 19, 1946' 2,415,952 Loomis Feb. 18, 1947 2,452,147 Reinhold et al. Oct. 26, 1948 FOREIGN PATENTS 972,202 France Oct. 23, 1950 

